Unblockable

"Hermione... is this what I think it is?"

"Third year Arithmancy text introduction... what of it?"

"Yeah... but this part specifically..."

"The Arithmetic breakdown of the Killing... Curse..." Hermione slowed to a stop as she stared at the book in Harry's hands. "Wizards can't be that stupid..."

"Think we could use this to modify an Obliviate to be unblockable?"

"Sometimes Harry, I don't know weither to kiss you or drag you off to a broom cupboard..."